At the time it wasn't that big a deal, as I had heat on the passenger side still but that rapidly deteriorated... I nursed it along through the winter and finally bit the bullet in July when it was super hot... and I had no A/C.

There were probably some more codes between feb and July, but I don't have my notes handy...

In digging I knew it was a lot of labor and I figured with 190k miles, I'd have everything replaced since I knew the Dash had to be completely taken apart anyway [as I didn't want to do the heater-treater solution at the time [if I had only known!]

So I took it to a mechanic (not jeep) and the following items were replaced:
1) Blend Box (the mid one)
2) re-circ box
3) right blend door actuator [was working at the time, but it's the one near the firewall, so I had it replaced since you have to tear apart the dash to get it.]
4) heater-core [same thing, had it replaced so we'd hopefully never have to go in there again]

Since then, I've had nothing but problems...
it's been back to the mechanic a number of times, and I've never had heat and cold working on both sides at the same time... I'll spare you all the back and forth and tell you the current situation (followed by a couple questions):

Current situation:
Heat & Cold on drivers side seem to work ok.
Cold on passengers side seems to work
Heat on passenger side... seems to not work... using an infrared heat gun I just did the following:

After running the car for a bit I used manual control (and made sure A/C was turned off) and an infrared heat gun to measure the vent temps:

Driver Door Vent: 140F
Center Console Vents: 150F
Passenger Side Vents: 110F [I also made sure to close and cover the right center vent so the air didn't bleed over the passenger vent]

I then cleared it (but couldn't clear 16, which I understand is an active as opposed to historic code)...

when I restarted, I still had 16... I restarted again, ran it for 10 minutes, running through the different modes, and ran the diagnostic again...
16 = Right temperature door not responding
52 = AI (Recirc) door travel range too large
54 = Left temperature door travel too large

I belive at one point I also had 56 or 46... I don't remember, I had done this a couple times before I decided to write it up.

Anyway, now that you have the background, question time [hopefully someone is still reading]:

1) Should there be a 40 degree difference in temp between left/center and right sides?
2) if not... what should the temp difference be?
3) Should I be getting the above fault codes?
4) any advice?

Owing to your experience that you donīt feel heat on the rh side and the fault code present (16), you can assume that the rh side blend door actuator is stuck/broken. Did you check the wiring/connector on the blend door actuator for any defects?When you remove the glove box, you can see the rh blend door actuator. Did you already try to errase all stored faults first by disconnecting the battery for a few minutes? When iīm not wrong, there is also a procedure mentioned on www.wjjeeps.com to calibrate the AZC system ( for the "blend door travel too large" messages you also have)

Here below a procedure from the jeep manual to manually control any electrical operated door in the AZC system ( just to rule out any other system problems). For the rh blend door actuator, you need to use test number 42.

OUTPUT CIRCUIT/ACTUATOR TESTS

In the Output Circuit/Actuator Test mode, the output
circuits can be viewed, monitored, overridden,
and tested. If a failure occurs in an output circuit,
test the circuit by overriding the system. Test the
actuator through its full range of operation.
(1) To begin the Output Circuit/Actuator Tests you
must be in the Select Test mode.
(2) With a 00 value displayed in the Test Selector
and no stick man, turn the rotary temperature control
knob until the test number you are looking for
appears in the Test Selector display. See the Circuit
Testing charts for a listing of the test numbers, test
items, test types, system tested, and displayed values.
(3) To see the output value, depress the a/c or
recirc button. The values displayed will represent the
output from the AZC control module.
(4) To enter the actuator test, depress the a/c or
recirc button. Then, rotate the right temperature set

I have to rectify myself, the rh blend door actuator you can not see through the glove box, that is the drivers side blend door actuator. In fact i have never seen it myself (and hope it will stay that way).Maybe you have seen it yourself when the dash was removed, not sure if you can see this actuator in any way with the dash in place.

I have to rectify myself, the rh blend door actuator you can not see through the glove box, that is the drivers side blend door actuator. In fact i have never seen it myself (and hope it will stay that way).Maybe you have seen it yourself when the dash was removed, not sure if you can see this actuator in any way with the dash in place.

Yeah, unfortunately, from what I can tell (and I don't know much about the A/C system other then what I picked up through various forums) the right door is controlled by the Actuator against the firewall. At the end of the day, I'm going to fight it out with the mechanic... they were claiming that it's fine...

Should there be a 40 degree difference in temp between left/center and right sides? what should the temp difference be?

Because there is a separate temperature regulation between driver and passenger, there can be a small difference when same temperature is selected, but i think this should not go over 10 degrees. There could be a problem with the infrared sensor, but you don't have any fault code for that one.I found the procedure for calibrating all the doors in the system, if you didn't find it yourself yet. Here it follows:

1. Turn the ignition on. 2. Set the HVAC to auto. 3. Turn the ignition off. 4. Remove IOD fuse. Wait 90 seconds before reinstalling. 5. Start the vehicle. You will hear sound of the doors moving. 6. Do not touch any of the AZC controls for at least one minute to allow the calibration function to run to completion. This forces the system into a recalibrate the full open and full closed position of the doors.

Did you try the procedure i had previously mentioned to control the passenger side blend door manually? Did it do anything?

When the system is ok, there should be no fault code present and only 00 should be shown.

Sorry for the delayed response, I was working through what you suggested and a couple of other things...

A quick update and some more questions:
1) the Code 16 turned out to be a loose wire in the connector harness [the mechanic needed to tear the whole dash apart again to get to that one

2) Even after taking the whole thing apart, I was still getting 52,54,56 codes... (Door range too far, left,right,recirc)

3) Yesterday we swapped out the 04' AZC module for one from a junkyark 03' so far, i'm not throwing codes, we'll see what happens.... but...

Prior to the swap, I have a new problem that's worrying me...

There's a strange smell when I drive the jeep inside the cabin, and it seems to be coming from the vents...
The best way I can describe it is:
A chemical like smell... similar to plastic or benzine or dry erase marker fumes. It's one of those things you don't immediately notice while in the car, but when you go out to fresh are, you smell it immediately, and then if you stick your head back in the car near the vents (I checked floor, and center console) you can definitely smell it... mechanic definitely smelled it yesterday too, and can't place it. He sprayed one of the commercial order removers that they use in case you have mold or something in the cooling system... but that didn't fix the problem (nor did I expect it too).

I've noticed this on as short a drive as one mile from a cold start. This definetly easn't there before I had all this work done on the jeep, I noticed it the first or second day I had it back, but thought it was just a "new plastic" smell... I don't think that's what it is any more.

Any idea of what this smell could be and/or how to diagnose and fix it?

Does this seem right from a cabin heat up perspective? I never remember it taking this long to get up to temp, but I've been fighting with it for so long, I want to make sure I'm not just hyper sensitive to it now.

So summary of problems I need help with:
1) Strange Smell... what needs to be done
2) Does it sound like the heat is working properly now?

Regarding the heating, seems to take quite some time to heat up the cabin. Was the fan somewhere in intermediate and not in low flow? When defrost is selected, automatically the A/C will work as well to lower the humidity of the air (and as a side effect, lower air temperatures as well). But i think the most important thing is that you feel yourself comfortable with the temperature inside the car. Here in Brazil i donīt use much the heater, but when i do, the air coming from the outlets is quite hot (with outside temp of approx 10 š C).How is the temperature pointer of the engine cooling liquid? With a thermostat sticking open or opening too soon, the cooling liquid doesnīt heat up enough and you get lower air temperatures in the cabin.Regarding the smell, was this there before the second dash teardown? I know the A/C system can give a bad smell, especially when just selected on, when there is some bacterial growth in the system. ( mine is like that at the moment and i have to take it to the A/C specialist to use a special spray to kill the germs).But i wonīt describe the smell as something plastic or chemical. I donīt hope the mechanic left or dropped some plastic bag or alike in one of the ducts and that its sticking on the heater core. Could explain the slow heating and smell...........

Regarding the heating, seems to take quite some time to heat up the cabin. Was the fan somewhere in intermediate and not in low flow? When defrost is selected, automatically the A/C will work as well to lower the humidity of the air (and as a side effect, lower air temperatures as well). But i think the most important thing is that you feel yourself comfortable with the temperature inside the car. Here in Brazil i donīt use much the heater, but when i do, the air coming from the outlets is quite hot (with outside temp of approx 10 š C).

I had the fan on high the whole time. I drive a lot in cold weather and I never remember it taking this long to heat up.

Quote:

Originally Posted by Frango100

How is the temperature pointer of the engine cooling liquid? With a thermostat sticking open or opening too soon, the cooling liquid doesnīt heat up enough and you get lower air temperatures in the cabin.

Seems to be about in the middle (not near the car right now).

Quote:

Originally Posted by Frango100

Regarding the smell, was this there before the second dash teardown?

At this point, I'm not positive, I think it was somewhere between the 2nd and 3rd dash teardown.

Quote:

Originally Posted by Frango100

I know the A/C system can give a bad smell, especially when just selected on, when there is some bacterial growth in the system. ( mine is like that at the moment and i have to take it to the A/C specialist to use a special spray to kill the germs).But i wonīt describe the smell as something plastic or chemical. I donīt hope the mechanic left or dropped some plastic bag or alike in one of the ducts and that its sticking on the heater core. Could explain the slow heating and smell...........

The mechanic used the bacteria spray 2 days ago, and that didn't help, but I'm pretty sure it's not bacteria. It's not really a melting plastic smell either... it's definitely more of a chemical smell, closer to paint thinner, benzene, two part epoxy, or dry erase markers.

Is the heater core an original MOPAR part, or is it parallel market stuff? Maybe they had painted the core, what gives the smell now when heating. It should disappear after some time when this is the case.Next time when heating the car, try not to use the defrost position too long and see if it heats up more quickly. (not using the airco this way)But i would also check the cooling liquid temperature to see if that is in the normal range.

I just wanted to take a moment to say thank you so much for this thread! I had to replace the blend door on my 2003 Grand Cherokee Overland and the replacement was simple enough, but I couldn't get it work correctly. I didn't know about the recalibration. Then this thread got me looking at wjjeeps for the AZC recalibration. That set me up. Thanx again guys!